Siemens S7-300 Installation And Operating Manual page 217

Communication error
Time monitoring activated
(watchdog)
EPROM fault
RAM fault
Processor failure
CRC signature error
Timeout of safety message
frame monitoring
Message frame error
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
Diagnostic message Possible causes of the problem
Error in communication between
the CPU and the module, for
example, due to defective
PROFIBUS connection or
electromagnetic interference in
excess of limits.
Timeout of safety message frame
monitoring
CRC signature error, for example,
due to electromagnetic
interference in excess of limits.
CPU is in STOP
Excessive electromagnetic
interference at times
Defective module
Excessive electromagnetic
interference at times
Defective module
Electromagnetic interference has
exceeded limits
Defective module
Switching rate exceeded
CRC signature error during
communication between the CPU
and the module has occurred, for
example, due to electromagnetic
interference in excess, faults
during sign-of-life monitoring error
or standard program accesses F-
SM.
Assigned monitoring time
exceeded
Startup of the fail-safe signal
module
Sign-of-life and/or CRC signature
entered in the data message
frame
Analog modules
9.2 SM 336; AI 6 x 13 Bit
Corrective measures
Check the PROFIBUS
connection
Eliminate the interference
Check the monitoring time
parameters
Eliminate the interference
Read the diagnostics buffer
Eliminate the interference
Replace the module
Eliminate the interference and
cycle power OFF/ON
Replace the module
Eliminate the interference
Replace the module
Reduce switching rate
Eliminate the interference
Check the monitoring time
parameters
—
Check the sign-of-life and CRC
signature entries in the data
message frame for "0" value
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